Many portable, battery-powered electronic devices such as radios, pagers, cassette recorders and the like have a covered battery compartment that is sized to accommodate several batteries and to interconnect them in a parallel or a serial configuration. The sides of the compartment have spiral spring terminals designed to forcedly contact the negative, bottom poles of the batteries, and stationary plates to contact their positive top located poles. Batteries, whether rechargeable or not, must be inserted one by one between pairs of such terminals. Other electronic instruments with a higher power draw such as video recorders accept a power pack housing a plurality of rechargeable power cells. A recharged power pack may be conveniently substituted for a run-down one in a few seconds.
It would be advantageous to replace the set of batteries of the first-described type of instrument by a rechargeable power pack which would fit in the battery compartment. However, the presence of the various spiral spring terminals and the battery-separating ribs that usually line the bottom of the battery compartment interfere with the insertion of such power packs.
Oftentimes, the length or width of the access to the battery compartment is shorter than the length of the batteries. The latter can only be installed by pressing each battery against one of the spiral terminals in order to clear the opposite edge of the opening. Accordingly, in-line battery packages such as those disclosed in U.S. Pat. No. 4,123,598 Hammel, whose outer-dimensions are necessarily similar to those of a set of installed batteries the package could replace, could not be inserted through such a restricted access; and particularly when spiral spring terminals are mounted on opposite sides of the battery compartment. Thus, until the instant invention, battery-powered devices have been equipped with compartments designed to accept either individually loaded batteries exclusively or with compartments designed to exclusively accept multi-cell power packages as disclosed in U.S. Pat. No. 5,061,579 Ishimoto. No rechargeable multi-cell power package has been provided that could fit within the battery compartment of a device not specifically built to accept it.
It would be even more advantageous to replace either the non-rechargeable batteries or the rechargeable power pack of an electronic device with a device, comprising rechargeable cells and a circuit allowing recharging during or after operation of the device. Preferably the device should be packaged into a housing shaped and dimensioned to nest into the device battery compartment in lieu of the batteries or power pack, and need not to be removed from the compartment during the recharging operation.
One of the problems encountered in making substitution of non-rechargeable power cells with a like number of rechargeable ones is the lesser rating voltage of the latter which may result in unacceptable power supply voltage levels.
Flexible contact members used in power supply packages can be damaged during insertion into an electronic device if they are caught by the surrounding structure. There is a need for more reliable contact assemblies.